The antonyms for more rookie are experienced, skilled, seasoned, veteran, adept, and proficient. These words describe someone who has gained knowledge and expertise through practice and hard work. A rookie, on the other hand, is someone who is new to a particular task or job and lacks knowledge and experience. An experienced individual can provide guidance, leadership, and mentorship to a rookie. Employers typically look for a combination of both rookies and experienced individuals to create a diverse and knowledgeable team. Ultimately, the opposite of a rookie is someone who has put in the time and effort to become an expert in their field.